Updated

Wal-Mart Stores Inc. is in the midst of its worst U.S. sales slump ever.

When it reports earnings on Tuesday, the retailer is widely expected to post its second straight year of declining domestic same-store sales.

Wal-Mart's struggles are the result of a misstep: To jump-start lethargic growth and counter the rise of competitors such as cheap-chic rival Target Corp., executives veered away from the winning formula of late founder Sam Walton to provide "every day low prices" to the American working class. Wal-Mart, the world's biggest retailer by sales, instead raised prices on some items while promoting deals on others.

Company executives acknowledge having miscalculated and are adjusting their strategy again. The big question is how quickly the mammoth chain can turn itself around.

Wal-Mart's shift from its traditional core customer manifested itself in numerous ways. A foray into organic foods didn't catch on with discount shoppers. A push to sell trendy fashions like skinny jeans bombed. And an attempt to cut clutter in stores to attract higher-income customers wound up undermining Wal-Mart's appeal to its traditional audience.

The Bentonville, Ark., chain's up-market push, which began before the recession, succeeded in attracting some well-heeled customers, but at great cost. Wal-Mart lost its iron grip on U.S. households earning less than $70,000 a year—which made up 68% of its domestic business—to other discounters.

"The basic Wal-Mart customer didn't leave Wal-Mart. What happened is that Wal-Mart left the customer," said former Wal-Mart executive Jimmy Wright, who supervised the company's distribution networks from 1992 to 1998 before leaving to co-found consulting firm Diversified Retail Solutions.

Continue reading at The Wall Street Journal